RESULTS:

Fifty-five patients completed this trial, which lasted from March 2007 to June 2009. Except for neutropenia, we found no differences in adverse events between the 2 groups. Compared with the placebo group, the HU group had -1.88 for GMFM (p = 0.11), -0.55 for MMT (p = 0.49), and 2.17 for flSMN mRNA (p = 0.13). Similarly, we found no difference in mean improvement of the secondary endpoints. Both groups had a trend toward a decline in FVC with little change in strength and motor function.

CONCLUSION:

Under the current regimen and schedule, HU brought about no improvement in patients with type 2 and 3 SMA, and its main side effect was neutropenia.

CLASSIFICATION OF EVIDENCE:

This trial provides Class I evidence that HU 20 mg/kg/day does not effectively treat SMA.